Recoil absorber for firearms



'.lan. l0, 1939. N. J. A. GALLIOT ET AL. 2,143,596

RECOIL ABSORBER FOR FIREARMS Filed July 8, A1955 B'Sheets-Sheet l Ln-vento@ attorney Jan 10, 1939. N. J. A. GALLloT ET AL 2,143,596

RECOIL ABSORBER FOR FIREARMS Filed July 8, 1935 2 Sheets-Sheet 2 Patented Jan. 10, 1939 `UNITED STATES PATENT OFFICE Norbert Jules Andr Galliot, Vancresson, and Jeanne Adrienne Victorine Anna Chbl Paris, France Application July 8, 1935, Serial No. 30,366 In France July 16, 1934 4 Claims.

weapon; the energy of the gases which escape' from the muzzle, is utilized to exert a force of traction in the contrary direction to the force producing the recoil of the weapon.

It is iound with these apparatus in general, when it is desired to obtain a suitable eiliciency, that they reject rearwardly burning and toxic gases of a nature to incommode the pointers and gun-servers, and have large weight and bulk, situated at the point where these characteristics have the most disadvantages, at the chase oi the weapon.

Numerous devices have been thought out in order to obviate these defects, in particular in order to trap the gases, to expand them and thereafter to send them back in a harmless direction, namely, even towards the front.

The device according to the invention proceeds from another idea; it tends to create in the gases, rejected into the atmosphere, a centrifugal force which results in urging,v them to take a direction transverse to the axis of the weapon and to become scattered in eddies in space; for this purpose, the gases, after having passed through the nozzle or nozzles and the corresponding deilector system or systems, are discharged directly into the atmosphere through -openings of helicoidal shape, the pitch of which is preferably shorter than that of the riiiing in the bore of the gun and shorter than the pitch of the helical ridges of the nozzles when the latter are helically ridged.

This device is especially applicable to guns intended for arming aircraft where the high speed of movement of the apparatus and the Very low temperature of the air in which it travels, aid the blowingout of the gases and their dispersion.

This arrangement allows of obtaining a reduction of the dimensions and weights, which may even reach a reduction of the diametrical overall size below two calibres.

In the annexed drawings:

Fig. 1 represents, by way of example, in a view partly in axial longitudinal sectioi, partly in external view, a form of carrying out the 'invention in its application to a three-expansion recoilabsorber', comprising three nozzles and the corresponding deflector-systerns.

Fig. 2 is a view in perspective of a modification of the muzzle check;

Fig. 3 is a view in side elevation of this modif cation, partly in vertical section, the muzzle check being represented in broken lines;

Fig. 4 is a view thereof in rear end elevation; Fig. 5 is a View in plan from above; and

Fig. 6 is a View in axial longitudinal section `of the muzzle check, showing a detail of construction of the latter. A

Referring to Fig. 1 of the drawings, a designates the barrel of a rearm, b a first convergentl5 divergent nozzle screwed to the front extremity of the barrel; c and d two other convergent-dif vergent nozzles, mounted in front of the iirst and iixed like the latter to the casing e; f designates an obturator, mounted in front of the third nozzle d and comprising a grooved cylindrical axial passage f1 for the discharge of the projectile; b1, c1, d1 l(each) designate an annular passage or throat, generated by the revolution, around the longitudinal axis -x of the barrel of the weapon of the curved profile of the rear face c2, d2, f2, turned towards the weapon, of the nozzles c, d and obturator f; these passages or throats b1, c1, dl constitute a kind of iixed deflector-systems. The nozzles l1, c, d are preferably of the type described in the French Patent No. 717,736 dated September 17, 1930, that is to sayv that they are grooved in such a way as to give the gases, passing through these nozzles, a movement of rotation around the axis of the letter, owing to the provision of helical ridges 123,03, d3. Of course, these helical ridges turn in the same direction as the rifling of the bore of the gun. Preferably, the pitch of helical ridges b3 is shorter than that of said riiling. In a likewise manner, the pitch of the ridges c3 of the second nozzle c will be shorter than that of ridges b3, and the pitch of the ridges d3 of the third nozzle d still shorter than that of the ridges c3 of the second'noziiin? The.gases,. thus animated with an extremely' 45 rapid movement of rotation around the axis -z of the weapon, will escape through the deiiector systems b1, c1, d1. They are then discharged directly into the atmosphere through openings e1, e2, e3 formed in the casing e: these openings 50 are of helical shape, in such a way as not to oppose the helicoidal rotation of the gases, but on the contrary to further accelerate the latter; with this object, the walls or arms g, which extend between these openings, are given the shape of helical surfaces, turning in a direction opposed to that of the grooving of the nozzles and preferably of a pitch still shorter than that ofthe'` grooving of the nozzles.

These arms or walls yg may be so arranged as not to coincide with the places where the ridges ofA the nozzles, if prolonged, would intersect the deiiectors, inforderto avoid the'formation of eddies which Would interferepwith the -flow and the efliciency.

The number of openings e1, e2, 'e3 and arms g kand their dimensions kcan vary according tothe assembly device has been worked out in order to conditions of each particular case.

o With this device, the gases are therefore urgedf to continue to turn in thev direction of therifling of the Weapon, but much faster and with a rearpurely and simply rejected towards the rear.,

, In the example .of construction represented, an

combine these desiderata, with as great as possible a reduction of the overall size.

The rst nozzleb comprises longitudinal beaks or extensions b4, which are preferably of the same number las the walls or arms g and which 351 f ngbetween the nozzle b and the corresponding present corresponding dimensions-y these beaks or' extensions?)A1 are arranged against the inner face `of the armsgand are :proled kin such a way as to `direct the gasesbetweenfthe latter, thusfairing these arms or Walls g internally; these beaks or extensionsserve moreover to regulate the spacdeilector-system c2.

The nozzles cand d comprise corresponding beaks or extensions c'1 and di, ,but` stronger `because they transmit a considerable portion of the thrust from the gases. n f

Ihe defiector-systems b1, c1 are constituted only in part by the curved rear face c2, d2 of the nozzles c, d respectively; an outer part of these dehector-systems b1, cl is constituted by an element ofthe rear face of the structure e, these parts being prefere-bly assembled in such mannerA as to form a step at z' in order to facilitatel the construction.

The casing c is fixed to the first nozzle b by a screw-threading and/or by tap-screws h.

This casing transmits the checking force by the arms y and the obturator f and eventually by the i and not by the beaks or extensions b4, c4, d4 of the nozzles b, c. d.

The assembling pins which serve likewise for the adjustment of the nal position of the parts, may be with heads showing or with countersunk head; in the oase where the casing is not screwthreaded internally, as represented at k, these pins support a portion of the forces by shear.

We have found that, in the case of firearms adapted to be mounted and to shoot close to the ground, the spent gases, rejected downwardly by the muzzle check, according to Fig. l, could make the dust fly and thus interfere with the sighting. Furthermore if the centrifugal action checks the discharge of the gases suiciently to preventit from producing a blast strong enough to bother the shooter, the acid nature oi the gases thus ref jected into the atmosphere `may disturb the latter and are connected to the latter, at the f front and rear, by transverse rings m and n re- `spectively;`r these plates l are preferably reinforced ing of the muzzle check and that they do not in- Two `steel plates yl are arranged, the one above and the other below the muzzle check A over the length of the crease too greatly the overall size of the apparaof the'muzzle check is practically nil, on condition that the ring m, sewing for the fixing of the blades at the rear upon the muzzle check (that .is to ysay on the side yof (towards) the shooter), has a frusto-conical shape, with the large base of the cone frustum towards the rear (Figs. 3 and 5) each platel isrconnected to the rear ring m by a wedge-shaped projection o, `of which the apex is situated upon the iront edge of the' ring mand which opens out towards the rear. f

Tests have shown that when the line of sight is lateral of the weapon, the wedge shaped member o, connecting the upper plate'l with the rear f lleft hand sidel of the .weapon l(lockingl towards thefront of the weapon, that is, on the left of Fig. 4 and on the upper half of'Fig. 5); in this case, the Wedge-shaped projection o, connecting the upper plate l to the rear ring m, should have a profile such as that indicated at o1, o2, o3, in Fig. 5, instead of the prole such as indicated at o4, o2, o3, in this same Fig. 5, This latter profile corresponds to the case where the line oi sight is situated in the longitudinal vertical axial plane of the weapon. In the first case, the face 01, o2 deflects the gases away from said plane more than does the face o4, o2 in the second case.

The front ring n must comprise a shoulder nl, in order to prevent'the escaping gases from pushing the device backwards. On the other hand, in order to prevent the helicoidal motion of the escaping gases from revolving the device, constituted by the plates l and the rings m, 1t, upon the muzzle check, the ring 1n is assembled to the casing of the muzzle check by pins (grub-screws) p. The latter further secure the device, consisting of plates l, l, in its position of maximum ei"- ciency, which is not that of the absolute horizontality of the plates, but a position slightly inclined to the horizontal, by reason of the helicoidal motion of the escaping gases. Fig. 4 represents this optimum position of inclination of the plates to the horizontal in the case of a weapon with right hand riiling.

Advantage can be taken of the shoulder or moulding nl on'the front ring'n in order to mount at this position a frusto-conical mouth-piece q preferably made of duralumin, forming a ilame screen in order to conceal the slight muzzle flash which the use of the device causes to reappear at the extremity of the 'muzzle check. In the case where the weight of the device described above or any other reason should make desirable a reinforcement of the muzzle check proper, this reinforcement can be obtained practically without increase of weight, by thi` arrangement represented in Fig. 6; each of the deflectors b1, c1, dl, comprises, behind its outlet edge, upon the casing e, a beading r, so that each of the arms or walls g, between the helicoidal openings e1, e2, e3 for the exit of the gases, is reinforced at the point where it is most subject to fatigue.

We claim:

l. A free exhaust recoil absorber for a gun having a barrel with a bore provided with riings which comprises, inv combination, at least one convergent-divergent nozzle at the `front end of said barrel, coaxial with said bore, inward ridges carried by the inner wall of said nozzle, disposed helically around the axis of said bore, with a pitch shorter than that of said riings, deflecting means rigid with saidnozzle opposite the periphery of the front end thereof for rejecting in a rearward direction the gases issuing from said nozzle, a plurality of radial partitions rigid with said deflecting means and disposed helically about the axis of said bore in the space existing between the outer front end of said nozzle and the outer rear face of said deflecting means, said helical partitions turning in a direction opposed to that of said riings and with a pitch shorter than that of said ridges, and two metallic plates rigid with said recoil absorber and disposed one above and the other below it, over the length thereof, so as to prevent the spent gases from interfering with the sighting.

2. A recoil absorber according to claim 1 further including rings for securing said plates to said recoil absorber at the vfront and rear part thereof.

3. A recoil absorber according to claim l in which said metallic plates are in a position slightly inclined to the horizontal, further including rings for securing said plates to said recoil absorber at the front and rear part thereof.

4. A free exhaust recoil absorber for a gun having a barrel with a bore provided with riflings, Which comprises, in combination, a plurality of convergent-divergent nozzles arranged one behind another at the muzzle end of said barrel, all coaxial with said bore, ridges carried by the inner wall of said nozzles, arranged helically around the axis of said bore, the pitch of the ridges of each nozzle being shorter than Athat of the ridges of the nozzle located nearer to the muzzle of the barrel and the pitch of the ridges of the nozzle immediately adjacent to the barrel being shorter than the pitch of the riflings of the said barrel, deecting members, rigid with said nozzles, located opposite the periphery of the front end of each of them for rejecting outwardly, in a transverse and somewhat rearward direction, directly into the atmosphere, the gases issuing from said nozzles, a plurality of radial partitions rigid with said deecting members and arranged helically about the axis of the bore in the space existing between the outer front end of each of the said nozzles and the outer rear face of the said deecting member located immediately ahead of said nozzle, said helical partitions turning in a direction opposed to that of the riings and of the ridges of the nozzles and with a pitch shorter than that of the said ridges, and outward projections on said deflecting members arranged to reinforce said partitions.

NORBERT JULES ANDRE' GALLIOT. JEANNE ADRIENNE VICTORINE ANNA CHBLE. 

